Work on it. You can try to just increase your activities (burn off) or you can do this and add some help. A visit with a clinical dietitian can help you plan a balanced nutrition that supports breastfeeding & meets your weight reduction goals. You can easily put 300 calories/day worth of loss through breastfeeding or loose a pound every 10 days.
Walk. It's ok to exercise while breastfeeding. If you're used to exercise, start slow-aim for a 30 minute walk with stroller daily. Both you and baby will benefit. Breastfeeding, in itself, will help you to burn more calories than a bottle feeding mom. Drink plenty of liquid-water is best.
I have a white spot in the center of my nipple. I am breast feeding. Is this clogged duct? Best way to get rid of? How long til it will go away?
Tricky. Dermatologic conditions are hard to discuss without seeing them. Depending on the size and other deformities, there might be a whitehead (mild infection needing antibiotics) or nothing much wrong at all.